20. Uluslararası Metalurji ve Malzeme Kongresi, İstanbul, Turkey, 10 June 2021
The solar light sensitive g-C3N4/TiO2 heterojunction nanocomposites were prepared in one step hydrothermal process by growing TiO2 nanoparticles on the surfaces of g-C3N4 particles. The g-C3N4 content of the composites varied from 20 to 90 wt%. The composite containing 80 wt% g-C3N4 was additionally subjected to a regulated heat treatment at different temperatures in the range from 350 to 500 oC for 1 h to improve the photocatalytic activity. XRD, FESEM, and DRS characterization techniques were applied to identify the crystalline phases present, to examine morphology developed, and to determine band gap energy of the composites. The Methylene Blue (MB) degradation tests were performed to evaluate the photocatalytic activity of the powders under solar light illumination using a UV-vis spectrophotometer. Results were compared with the results of the phase pure TiO2 and phase pure g-C3N4 powders. The g-C3N4/TiO2 heterojunction photocatalysts exhibited better photocatalytic activity for the degradation of MB than both TiO2 and g-C3N4 powders. The improvement in photocatalytic activity was attributed to the generation of reactive oxidation species induced by photogenerated electrons and to the reduced recombination rate for electron-hole pairs.